Many devices known in the art are useful for protecting power sources from electrical faults. There are at least three types of electrical faults: a ground fault, a transient fault, and an arc fault. A ground fault occurs when a grounded conductor comes into contact with electrical circuitry, causing an excessive current flow in that circuitry. A transient fault occurs when a grounded conductor briefly comes into contact with an electrical circuitry, causing a temporary excessive current flow in that circuitry. As a result of the excessive current drawn by ground and transient faults, power supplies can become overloaded, and the load that a power supply is meant to power ends up receiving little or no current. An arc fault occurs when an arc is struck between two conductors that are not in physical contact but are close to each other. An arc can produce high temperatures in its vicinity, which can create a fire hazard.
Existing devices for protecting power sources from electrical faults use thermal sensors, magnetic sensors, and/or current sensors to detect electrical faults. For these devices, it is necessary to select and calibrate their sensors to accommodate the current drawn by the load for proper operation, making the existing fault protection devices load dependent. The process of selecting and calibrating particular sensors to the current drawn by the load is time consuming and expensive. Furthermore, these sensors must be recalibrated when the current drawn by the load changes significantly or if a different load is used.
Accordingly, there exists a need for an electrical fault detection and protection device that operates independently of the load so that no calibration of the sensor is needed and is cost-effective to construct.